This invention relates to a double valve arrangement used for a pressurized beer keg, said arrangement comprises a safety device in order to prevent a valve body popped out of the keg under pressure causing unintended personal injury, or when the dismount is handled by somebody who is unauthorized to do so.
In public places like restaurants or pubs where beer is served, kegs are commonly used. The keg is highly pressurized with carbon dioxide gas inside. When serving beer out of the keg into a drinking glass, more carbon dioxide gas is pressed into the keg through a gas valve, making it possible to dispense the beer out through a liquid valve. Thus, a double valve arrangement, installed in the insect part of the keg, serves dual purposes, one for gas passage, and the other for liquid passage. When the keg is empty, it is returned to a beverage manufacturer for recycling and refill. The keg has to be cleaned prior to the procedure of refilling it with beer. When a worker detaches the valve arrangement away from the keg for cleaning purpose, it is often difficult for him to know whether there remains any of the gas pressure within the keg. The valve body, when being dismounted from the keg, could pop out suddenly due to the possible gas pressure that remains within the container, causing serious personal injury to the one who bends working on it. In addition, when the keg is handled by somebody who is either unauthorized to do so, or ignorant of the potential danger, same serious result could also ensure.
Several designs and ideas have been proposed with an intent to solve this particular problem. According to a UK patent (2,188,040), a valve body is formed with a projection having radical extent and axial location that the valve body can be moved down through the keg neck ring when separate from the valve housing. But the valve housing and the valve body can be coupled together only after the valve body with its projection has been moved down through the neck ring. Since the device cannot be inserted into the keg dispensing aperture in a fully assembled condition, it is often considered inconvenient and time-consuming for operation and handling.
Another U.S. Pat. No. (5,653,253), comprises a catch with a vertically, downwardly converging wedge, the edge of which protrudes through the housing window to prevent the passage of the valve through the opening of the neck ring. However, in addition to a spanner to dismantle the valve body, there must also be a de-activation rod in order to fully pull the valve body out. Thus it is not convenient to handle the dismount procedure in solving the problem.
A recent U.S. Pat. No. (5,833,098) has been proposed with an idea of a stopper to prevent the propping out of the spear tube by hooking the stopper portion to the keg neck interface. But it is only possible to completely detach the spear tube from the beer keg with the aid of both a tool and a jig, in that the tool is rotated on the axial center of the spear tube and the jig is employed to pull the stopper portion into an inside of the body before a complete detachment can possibly be achieved.
These conventional designs, as well as some others, while attempting to serve the purpose of the prevention of the valve body propping out of the beer keg, are inconvenient to operate in practice, and are also complicated in design.
It is an object of the present invention to provide an improved double valve arrangement to prevent the propping out of the valve body either unintended or unauthorized, by means of a simple safety device that avoids disadvantages of inconvenience and complicated designs.
The safety device, under the present invention, can be inserted into the beer keg dispensing aperture as a wholly assembled piece by being pushed down into it axially and screwed tight, and it can be pulled out as a whole piece by a special tap.
According to the present invention, a double valve body is formed with a locking member disposed between a down pipe and a housing. Extended from the locking member there are two bendings in opposite directions, one of which inwardly in contact with the down pipe, and the other outwardly secured to the housing. The flaps of the locking member normally protrude out to prevent the detachment of the valve body out of the beer keg neck ring. When a special tap is employed to push against the double valve body, the down pipe moves downward, and the direction of the inward bending of the locking member changes accordingly, along from a lower portion of the down pipe to an enlarged portion of the down pipe, which results in the movement of the locking member, retrieving the flaps to the inside of the housing in order that the valve body could be moved out without any difficulty. The special tap is only available to the authorized personnel at the manufacturers.